/usr/include/boost/spirit/home/qi/detail
Edit: /usr/include/boost/spirit/home/qi/detail/attributes.hpp (4611B)
// Copyright (c) 2001-2011 Hartmut Kaiser
// Copyright (c) 2001-2011 Joel de Guzman
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
#ifndef BOOST_SPIRIT_QI_DETAIL_ATTRIBUTES_HPP
#define BOOST_SPIRIT_QI_DETAIL_ATTRIBUTES_HPP
#include
#include
#include
#include
///////////////////////////////////////////////////////////////////////////////
namespace boost { namespace spirit { namespace qi
{
template
struct default_transform_attribute
{
typedef Transformed type;
static Transformed pre(Exposed&) { return Transformed(); }
static void post(Exposed& val, Transformed const& attr)
{
traits::assign_to(attr, val);
}
// fail() will be called by Qi rule's if the rhs failed parsing
static void fail(Exposed&) {}
};
// handle case where no transformation is required as the types are the same
template
struct default_transform_attribute
{
typedef Attribute& type;
static Attribute& pre(Attribute& val) { return val; }
static void post(Attribute&, Attribute const&) {}
static void fail(Attribute&) {}
};
template
struct proxy_transform_attribute
{
typedef Transformed type;
static Transformed pre(Exposed& val) { return Transformed(val); }
static void post(Exposed&, Transformed const&) { /* no-op */ }
// fail() will be called by Qi rule's if the rhs failed parsing
static void fail(Exposed&) {}
};
// handle case where no transformation is required as the types are the same
template
struct proxy_transform_attribute
{
typedef Attribute& type;
static Attribute& pre(Attribute& val) { return val; }
static void post(Attribute&, Attribute const&) {}
static void fail(Attribute&) {}
};
// main specialization for Qi
template
struct transform_attribute
: mpl::if_<
mpl::and_<
mpl::not_ >
, mpl::not_ >
, traits::is_proxy >
, proxy_transform_attribute
, default_transform_attribute
>::type
{};
template
struct transform_attribute, Transformed
, typename disable_if, Transformed> >::type>
{
typedef Transformed& type;
static Transformed& pre(boost::optional& val)
{
if (!val)
val = Transformed();
return boost::get(val);
}
static void post(boost::optional&, Transformed const&) {}
static void fail(boost::optional& val)
{
val = none; // leave optional uninitialized if rhs failed
}
};
// unused_type needs some special handling as well
template <>
struct transform_attribute
{
typedef unused_type type;
static unused_type pre(unused_type) { return unused; }
static void post(unused_type, unused_type) {}
static void fail(unused_type) {}
};
template <>
struct transform_attribute
: transform_attribute
{};
template
struct transform_attribute
: transform_attribute
{};
template
struct transform_attribute
: transform_attribute
{};
}}}
///////////////////////////////////////////////////////////////////////////////
namespace boost { namespace spirit { namespace traits
{
namespace detail {
template
struct transform_attribute_base
: qi::transform_attribute
{};
}
}}}
#endif